1999 Toyota 4Runner 6 cyl Four Wheel Drive Automatic 140K miles
I have been getting the code P 0171, "Engine running too lean" on my 1999 Toyota 4Runner (3.4, 6 cyl.) Over the past year.
When the light first came on, I replace both O2 sensors. The light stayed off for about a month.
I then took it to a shop, and had vacuum lines reconnected, the spark plugs and wires replaced, and had diagnostics done. The mechanic told me that the 4Runner was throwing all kinds of fuel at the engine, but it wasn't making through the system properly. That makes sense, because my exhaust smells rich, but there is reduced power and gas mileage. The mechanic was unable to fix the problem.
After spending my available repair funds at the shop, and still having a check engine light on, I did more research, bought some MAF sensor cleaner, cleaned the MAF sensor, and the light went off, and the car ran fine.
The light came back on a month later.
I then replaced the MAF sensor all together. No change.
It has started idling low enough to stall, and is hesitating to start randomly.
Air filter and fuel filter have also been replaced in the last 6 months.
have the same problem?
Monday, June 29th, 2009 AT 9:17 AM